1. Field of the Invention
This invention relates generally to the monitoring and analysis of pressure data for the control of body support systems, including mattresses and other bedding systems.
2. Description of the Related Art
The performance of mattress and other bedding and body support systems depends in part on the amount of pressure and the distribution of pressure experienced by different parts of the body. Pressure mapping systems have been used to assess support surfaces and compare performance differences for different body types. Pressure mapping systems have also been used to design and test active bedding systems that are intended to minimize pressure across the body for medical and commercial applications. Pressure sensors have also been used to monitor bed pressure in order to reduce pressure where the bed contacts the body. However, simply reducing pressure on the body does not optimize the balance between comfort and support.
“Comfort” is commonly described as the way the surface of the mattress feels against the surface of your body. It can be a personal and subjective assessment of the mattress but there are mattress attributes that are known to impact this perception of comfort. The perception of comfort is primarily affected by the upholstery layers, particularly the cushioning and quilting. Mattress companies typically use words like “firm,” “plush,” and “pillow-top” to describe the comfort attributes of a bed, but this is simply a way of categorizing the softness or hardness of the surface layers. Other comfort-related attributes include features that minimize disturbance from your partner's movements, or that provide for differing levels of comfort on each side of the bed.
Comfort can be defined as a state of physical ease and freedom from pain or constraint. In the sleep industry, bedding systems are designed to provide maximum comfort by reducing pressure points on the body. For example, one manufacturer believes that pressures on the body must not exceed 0.5 pounds per square inch in order to maximize comfort. This pressure limit was chosen because it is generally accepted to be the point where blood circulation begins to be constricted and muscle tension begins to form. The end result of muscle tension and restricted blood flow is restless tossing and turning.
Bedding systems implement a wide variety of methods to reduce pressure points on the body. Latex or “memory foam,” pocket coils, adjustable air beds, water beds, and pillow style “topper” layers are common technologies used to provide comfort by reducing pressure points. These systems work by increasing contact area and as a result the body pressure is distributed more evenly. However, there is a point where the redistribution of pressure via a softer bedding system can compromise the support of the mattress and this can result in back pain, feeling restricted and a less restful sleep.
“Support” commonly refers to the aspects of the bed that push back in order to hold your spine in position while you sleep. Unlike with comfort, which is largely a matter of personal preference, everyone requires some support from their mattress. Improper or inadequate support can result in tension or back pain, as your muscles try to compensate to keep your spine in alignment, and frequently causes pain and/or stiffness when you wake up. Though mattress companies use words like “firm” or “extra firm” to explain the support provided by a bed, what they are really describing is the extent to which the inner core of the mattress is “springy” or “stiff.” The sleep surface should hold the spine as closely as possible to its natural alignment regardless if you are a back or side sleeper. However, the support requirements can be very different between side and back sleeping.
Bedding systems implement a wide variety of methods to provide support. Latex foam mattresses typically have a firmer inner layer to provide better support over the softer outer layer. In an innerspring mattress, support is driven primarily by the spring coils, both in their quantity and their construction. Pocket coils are know for providing exceptional support as they can provide varying and appropriate levels of support to different areas of the body, for example, head, chest, hips, or ankles. Air beds and water beds use fluid as the inner support layer and are fully customizable in terms of the firmness or support provided by the adjustable core.
Bedding system manufacturers typically offer a wide array of systems that provide varying degrees of firmness at both the outer layers (comfort layer) and the inner layers (support layer). This allows a customer to find a match for their body type and personal preferences.
However, support and comfort needs are known to change based on a person's body position or state of sleep. When buying a mattress it is common to be asked if you are a side sleeper or a back sleeper because the support requirements are usually very different between these positions. However, it is unnatural to spend all of your time sleeping in one position. Therefore, purchasing or configuring your bed to favour one position over another is a compromise at best.
Bedding systems that attempt to actively monitor pressure and make continuous adjustments typically rely on the process of trying to minimize pressure on all points of the body. However, focusing on minimizing pressure can lead to a bed surface that is too soft and provides inadequate support to ensure a restful and pain free sleep.
Therefore, there is a need for a bedding system that adjusts the support and comfort of the system in response to changing conditions.